2. Measuring soil respiration: Lundegårdt‘s respiration bell, (Lundegårdt 1922, 24 )

3. Where are we today? (about 80 years after Lundegård) Thanks to LiCor there has not been much technical progress. There are tons of data. We need more comprehensive studies. We need additional information about soil properties, root dynamics, mycorrhizae, microbes… (the actors). We need better models. We need a database!

4. ‚Potentials and limitations of an international soil respiration database‘, Crete 9.-11.11.2006 Goals of the workshop: Technical aspects are fundamental design of the database: Questions of web-based data input and output, data management and maintenance of the database. In this context it is very important to find an institution that will be able to host and maintain this database with a long-term perspective. Another technical aspect has to be the copyright on the submitted data and the data use policy. The balance between open data access and the protection of the copyright of the submitting scientist is always a crucial point for the success of databases.

5. ‚Potentials and limitations of an international soil respiration database‘ Goals of the workshop: Scientific aspects will focus on a common protocol for measurement techniques, site description and additional parameters. Since it has been shown in previous studies that neither latitude nor climate can reliably explain differences between sites, additional information is required in order to ensure the base for reasonable comprehensive studies. In addition, a session on scientific aspects will summarize existing knowledge from comprehensive studies and derive perspectives for future approaches. 3-5 Scientific prototype studies.

6. Detailed soil respiration data base (methods, soil descriptions…) Fluxes Soil Resp. Inventor. Remote sensing maps IMECC ‚Simple‘ presentation database Uncertainty flags… Suggested data base structure:

7. Collar name (Individual Sample Code) Efflux [µmol CO2 m-2 s-1] Soil moisture [% Vol] Measurement Timestamp [UTC] Depth [m] Measurement method Method code (ODS/CDS/…) Description Number of collars Insertion depth of collars Distance of sensors to chamber MeasurementMeasurement method Equipment IRGA/SLW/… Calibration interval Project Sampling design (e.g. spatial distribution) Contributors / Institutes Contact Person Additional Info Soil temperature [°C] Equipment Sensor for soil temperature Sensor for soil moisture Soil Layer - At least for reference plot - Name / Thickness [m] Density [g dry soil cm-3] Stone content / pH (in water) Texture C-concentration [mg g-1] N-concentration [mg g-1] P-concentration [mg g-1] Root biomass / Microbial biomass CO2-production under standard lab conditions [Basal respiration] Measurement method Climate Data Annual Means Description Soil characterization Reiner Krause, Max-Planck-Institute for Biogeochemistry, Jena, 08.11.2006 Plot Zone (Type of plot) Location Site name / Country Region / Altitude Latitude / Longitude NPP, Eddy?... All additional measurements Link, where to find Site

8. Quality check by PI We might offer some tools for aggregation (to calculate annual sums).

9. How to become part of the community? Join the mailing list by mailing to: wkutsch@bgc-jena.mpg.de There will be a website: www.soilrespiration.net Send data: up to now as a simple sheet to: wkutsch@bgc-jena.mpg.de

10. Data policy Two levels of data: Level 1:Open data, direct download Level 2: Permission requested Users have to accept some basic rules: Information of the PIs about an ongoing project Level 1: fair citation and acknowledgement Level 2: discussion about co-authorship At all levels: offer co-authorships in case of intellectual input

11. Working group 1: Making data comparable for comprehensive studies Pavelka et al., subm. Plant & Soil

12. Working group 1: Making data comparable for comprehensive studies

13. Working group 1: Making data comparable for comprehensive studies Comparing Q 10 -values at different time scales. Identify factors co-varying with temperature, that cause the apparent high Q 10 -values at annual time scales

14. Working group 2: For data from EC sites: Detection and quantification of photosynthetic signal in soil respiration Tang et al., 2005 GCB Figure 8. Response to cumulative GPP of the previous day for (a) rhizosphere, (b) mycorrhizal and (c) mycorrhizosphere respiration. The relation was not significant for the rhizosphere component (r2=0.324, n=12, p=0.53) but significant for mycorrhizal respiration (r2=0.79, n=12, p<0.001). The more commonly measured sum of both, mycorrhizosphere respiration, also showed a significant correlation (r2=0.69, n=12, p<0.01). Moyano et al., (i.p.) SBB

15. Data request by the photosynthesis group: Continuous SR (half-hourly – hourly) data for at least 2 months during the vegetation period. Measured in the footprint of an EC tower. Eddy covariance data. Additional data from the site: Meteo, Soil properties, LAI, NPP… Coordinator: Jorge Curiel Yuste, Berkeley jkuriel@nature.berkeley.edu

16. Additional studies from these data u* correction of nighttime NEE using nighttime continuous measurements of soil respiration. Bernard Longdoz longdoz@nancy.inra.fr Vertical distribution of soil CO 2 production in relation to soil CO 2 efflux. Jukka Pumpanen jukka.pumpanen@helsinki.fi

17. WG 3: Comparison between continuous soil temperature/moisture data and discontinuous SR measurements Hainich 2005 – comparison between continuous measurements of soil temperature and moisture and SR measurements

18. Annual total (all data): 7.93 tC ha -1 (Model R 2 = 0.90) Annual total (reduced dataset): 8.40 tC ha -1 (Model R 2 = 0.69) Mirco Rodeghiero, i.p.

19. Ask for permission!!! Two more working groups: Model/Data comparison. How to merge soil respiration data with detailed studies of microbial community ecology.

20. Ask for permission!!! Grab your recent data! Go to your data-cemetery and dig out old data sets. (We accept even 5¼’ Floppies)! Send data: up to now as a simple sheet to: wkutsch@bgc-jena.mpg.de

21. http://www.rstcb.alterra.nl Final conference of the programme: Trends in EU Soil Carbon Pools Date: 6 - 9 May 2007 Location:Wageningen International Conference Centre (WICC), Lawickse Allee 9, 6701 AN Wageningen, The Netherlands